Electron Emission, Photo Electric Effect (Threshol Frequency Stopping Potential)
Dual nature of radiation and Matter

142146 Two identical photocathodes receive light of frequencies $f_{1}$ and $f_{2}$. If the velocities of the photoelectrons of mass $m$ coming out are respectively $v_{1}$ and $v_{2}$, then

1 $v_{1}^{2}-v_{2}^{2}=\frac{2 h}{m}\left(f_{1}-f_{2}\right)$
2 $\mathrm{v}_{1}+\mathrm{v}_{2}=\left[\frac{2 \mathrm{~h}}{\mathrm{~m}}\left(\mathrm{f}_{1}+\mathrm{f}_{2}\right)\right]^{1 / 2}$
3 $\mathrm{v}_{1}^{2} \mathrm{v}_{2}^{2}=\frac{2 \mathrm{~h}}{\mathrm{~m}}\left(\mathrm{f}_{1}+\mathrm{f} 2\right)$
4 $\mathrm{v}_{1}-\mathrm{v}_{2}=\left[\frac{2 \mathrm{~h}}{\mathrm{~m}}\left(\mathrm{f}_{1}-\mathrm{f}_{2}\right)\right]^{1 / 2}$
Dual nature of radiation and Matter

142147 The graph $\frac{1}{\lambda}$ and stopping potential (V) of three metals having work function $\phi_{1}, \phi_{2}$ and $\phi_{3}$ in an experiment of photoelectric effect is plotted as shown in the figure. Which one of the following statement is /are correct? [Here $\lambda$ is the wavelength of the incident rayl

(I) Ratio of work functions $\phi_{1}: \phi_{2}: \phi_{3}=1: 2: 4$
(II) Ratio of work functions $\phi_{1}: \phi_{2}: \phi_{3}=4: 2: 1$
(III) $\operatorname{Tan} \theta \propto \frac{\mathrm{hc}}{\mathrm{e}}$ where $\mathrm{h}=$ Planck's constant, $\mathrm{c}=$ speed of light
(IV) The violet colour-light can eject photoelectrons from metals 2 and 3

1 (i), (iii)
2 (i), (iv)
3 (ii), (iii)
4 (i), (ii) and (iv)
Dual nature of radiation and Matter

142148 Photoelectric emission is observed from a metallic surface for frequency $v_{1}$ and $v_{2}$ of the incident light $\left(v_{1}>v_{2}\right)$. If the maximum values of kinetic energy of the photoelectrons emitted in the two cases are in the ratio $1: n$, then the threshold frequency of the metallic surface is

1 $\frac{\left(v_{1}-v_{2}\right)}{(n-1)}$
2 $\frac{\left(\mathrm{n} v_{1}-v_{2}\right)}{(\mathrm{n}-1)}$
3 $\frac{\left(\mathrm{n} v_{2}-v_{1}\right)}{(\mathrm{n}-1)}$
4 $\frac{\left(v_{1}-v_{2}\right)}{n}$
Dual nature of radiation and Matter

142150 In photoelectric effect, the work function of a metal is $3.5 \mathrm{eV}$. The emitted electrons can be stopped by applying a potential of $-1.2 \mathrm{~V}$. Then,

1 the energy of the incident photons is $4.7 \mathrm{eV}$
2 the energy of the incident photons is $2.3 \mathrm{eV}$
3 if higher frequency photons be used, the photoelectric current will rise
4 When the energy of photons is $3.5 \mathrm{eV}$, the photoelectric current will be maximum
NEET Test Series from KOTA - 10 Papers In MS WORD WhatsApp Here
Dual nature of radiation and Matter

142146 Two identical photocathodes receive light of frequencies $f_{1}$ and $f_{2}$. If the velocities of the photoelectrons of mass $m$ coming out are respectively $v_{1}$ and $v_{2}$, then

1 $v_{1}^{2}-v_{2}^{2}=\frac{2 h}{m}\left(f_{1}-f_{2}\right)$
2 $\mathrm{v}_{1}+\mathrm{v}_{2}=\left[\frac{2 \mathrm{~h}}{\mathrm{~m}}\left(\mathrm{f}_{1}+\mathrm{f}_{2}\right)\right]^{1 / 2}$
3 $\mathrm{v}_{1}^{2} \mathrm{v}_{2}^{2}=\frac{2 \mathrm{~h}}{\mathrm{~m}}\left(\mathrm{f}_{1}+\mathrm{f} 2\right)$
4 $\mathrm{v}_{1}-\mathrm{v}_{2}=\left[\frac{2 \mathrm{~h}}{\mathrm{~m}}\left(\mathrm{f}_{1}-\mathrm{f}_{2}\right)\right]^{1 / 2}$
Dual nature of radiation and Matter

142147 The graph $\frac{1}{\lambda}$ and stopping potential (V) of three metals having work function $\phi_{1}, \phi_{2}$ and $\phi_{3}$ in an experiment of photoelectric effect is plotted as shown in the figure. Which one of the following statement is /are correct? [Here $\lambda$ is the wavelength of the incident rayl

(I) Ratio of work functions $\phi_{1}: \phi_{2}: \phi_{3}=1: 2: 4$
(II) Ratio of work functions $\phi_{1}: \phi_{2}: \phi_{3}=4: 2: 1$
(III) $\operatorname{Tan} \theta \propto \frac{\mathrm{hc}}{\mathrm{e}}$ where $\mathrm{h}=$ Planck's constant, $\mathrm{c}=$ speed of light
(IV) The violet colour-light can eject photoelectrons from metals 2 and 3

1 (i), (iii)
2 (i), (iv)
3 (ii), (iii)
4 (i), (ii) and (iv)
Dual nature of radiation and Matter

142148 Photoelectric emission is observed from a metallic surface for frequency $v_{1}$ and $v_{2}$ of the incident light $\left(v_{1}>v_{2}\right)$. If the maximum values of kinetic energy of the photoelectrons emitted in the two cases are in the ratio $1: n$, then the threshold frequency of the metallic surface is

1 $\frac{\left(v_{1}-v_{2}\right)}{(n-1)}$
2 $\frac{\left(\mathrm{n} v_{1}-v_{2}\right)}{(\mathrm{n}-1)}$
3 $\frac{\left(\mathrm{n} v_{2}-v_{1}\right)}{(\mathrm{n}-1)}$
4 $\frac{\left(v_{1}-v_{2}\right)}{n}$
Dual nature of radiation and Matter

142150 In photoelectric effect, the work function of a metal is $3.5 \mathrm{eV}$. The emitted electrons can be stopped by applying a potential of $-1.2 \mathrm{~V}$. Then,

1 the energy of the incident photons is $4.7 \mathrm{eV}$
2 the energy of the incident photons is $2.3 \mathrm{eV}$
3 if higher frequency photons be used, the photoelectric current will rise
4 When the energy of photons is $3.5 \mathrm{eV}$, the photoelectric current will be maximum
Dual nature of radiation and Matter

142146 Two identical photocathodes receive light of frequencies $f_{1}$ and $f_{2}$. If the velocities of the photoelectrons of mass $m$ coming out are respectively $v_{1}$ and $v_{2}$, then

1 $v_{1}^{2}-v_{2}^{2}=\frac{2 h}{m}\left(f_{1}-f_{2}\right)$
2 $\mathrm{v}_{1}+\mathrm{v}_{2}=\left[\frac{2 \mathrm{~h}}{\mathrm{~m}}\left(\mathrm{f}_{1}+\mathrm{f}_{2}\right)\right]^{1 / 2}$
3 $\mathrm{v}_{1}^{2} \mathrm{v}_{2}^{2}=\frac{2 \mathrm{~h}}{\mathrm{~m}}\left(\mathrm{f}_{1}+\mathrm{f} 2\right)$
4 $\mathrm{v}_{1}-\mathrm{v}_{2}=\left[\frac{2 \mathrm{~h}}{\mathrm{~m}}\left(\mathrm{f}_{1}-\mathrm{f}_{2}\right)\right]^{1 / 2}$
Dual nature of radiation and Matter

142147 The graph $\frac{1}{\lambda}$ and stopping potential (V) of three metals having work function $\phi_{1}, \phi_{2}$ and $\phi_{3}$ in an experiment of photoelectric effect is plotted as shown in the figure. Which one of the following statement is /are correct? [Here $\lambda$ is the wavelength of the incident rayl

(I) Ratio of work functions $\phi_{1}: \phi_{2}: \phi_{3}=1: 2: 4$
(II) Ratio of work functions $\phi_{1}: \phi_{2}: \phi_{3}=4: 2: 1$
(III) $\operatorname{Tan} \theta \propto \frac{\mathrm{hc}}{\mathrm{e}}$ where $\mathrm{h}=$ Planck's constant, $\mathrm{c}=$ speed of light
(IV) The violet colour-light can eject photoelectrons from metals 2 and 3

1 (i), (iii)
2 (i), (iv)
3 (ii), (iii)
4 (i), (ii) and (iv)
Dual nature of radiation and Matter

142148 Photoelectric emission is observed from a metallic surface for frequency $v_{1}$ and $v_{2}$ of the incident light $\left(v_{1}>v_{2}\right)$. If the maximum values of kinetic energy of the photoelectrons emitted in the two cases are in the ratio $1: n$, then the threshold frequency of the metallic surface is

1 $\frac{\left(v_{1}-v_{2}\right)}{(n-1)}$
2 $\frac{\left(\mathrm{n} v_{1}-v_{2}\right)}{(\mathrm{n}-1)}$
3 $\frac{\left(\mathrm{n} v_{2}-v_{1}\right)}{(\mathrm{n}-1)}$
4 $\frac{\left(v_{1}-v_{2}\right)}{n}$
Dual nature of radiation and Matter

142150 In photoelectric effect, the work function of a metal is $3.5 \mathrm{eV}$. The emitted electrons can be stopped by applying a potential of $-1.2 \mathrm{~V}$. Then,

1 the energy of the incident photons is $4.7 \mathrm{eV}$
2 the energy of the incident photons is $2.3 \mathrm{eV}$
3 if higher frequency photons be used, the photoelectric current will rise
4 When the energy of photons is $3.5 \mathrm{eV}$, the photoelectric current will be maximum
Dual nature of radiation and Matter

142146 Two identical photocathodes receive light of frequencies $f_{1}$ and $f_{2}$. If the velocities of the photoelectrons of mass $m$ coming out are respectively $v_{1}$ and $v_{2}$, then

1 $v_{1}^{2}-v_{2}^{2}=\frac{2 h}{m}\left(f_{1}-f_{2}\right)$
2 $\mathrm{v}_{1}+\mathrm{v}_{2}=\left[\frac{2 \mathrm{~h}}{\mathrm{~m}}\left(\mathrm{f}_{1}+\mathrm{f}_{2}\right)\right]^{1 / 2}$
3 $\mathrm{v}_{1}^{2} \mathrm{v}_{2}^{2}=\frac{2 \mathrm{~h}}{\mathrm{~m}}\left(\mathrm{f}_{1}+\mathrm{f} 2\right)$
4 $\mathrm{v}_{1}-\mathrm{v}_{2}=\left[\frac{2 \mathrm{~h}}{\mathrm{~m}}\left(\mathrm{f}_{1}-\mathrm{f}_{2}\right)\right]^{1 / 2}$
Dual nature of radiation and Matter

142147 The graph $\frac{1}{\lambda}$ and stopping potential (V) of three metals having work function $\phi_{1}, \phi_{2}$ and $\phi_{3}$ in an experiment of photoelectric effect is plotted as shown in the figure. Which one of the following statement is /are correct? [Here $\lambda$ is the wavelength of the incident rayl

(I) Ratio of work functions $\phi_{1}: \phi_{2}: \phi_{3}=1: 2: 4$
(II) Ratio of work functions $\phi_{1}: \phi_{2}: \phi_{3}=4: 2: 1$
(III) $\operatorname{Tan} \theta \propto \frac{\mathrm{hc}}{\mathrm{e}}$ where $\mathrm{h}=$ Planck's constant, $\mathrm{c}=$ speed of light
(IV) The violet colour-light can eject photoelectrons from metals 2 and 3

1 (i), (iii)
2 (i), (iv)
3 (ii), (iii)
4 (i), (ii) and (iv)
Dual nature of radiation and Matter

142148 Photoelectric emission is observed from a metallic surface for frequency $v_{1}$ and $v_{2}$ of the incident light $\left(v_{1}>v_{2}\right)$. If the maximum values of kinetic energy of the photoelectrons emitted in the two cases are in the ratio $1: n$, then the threshold frequency of the metallic surface is

1 $\frac{\left(v_{1}-v_{2}\right)}{(n-1)}$
2 $\frac{\left(\mathrm{n} v_{1}-v_{2}\right)}{(\mathrm{n}-1)}$
3 $\frac{\left(\mathrm{n} v_{2}-v_{1}\right)}{(\mathrm{n}-1)}$
4 $\frac{\left(v_{1}-v_{2}\right)}{n}$
Dual nature of radiation and Matter

142150 In photoelectric effect, the work function of a metal is $3.5 \mathrm{eV}$. The emitted electrons can be stopped by applying a potential of $-1.2 \mathrm{~V}$. Then,

1 the energy of the incident photons is $4.7 \mathrm{eV}$
2 the energy of the incident photons is $2.3 \mathrm{eV}$
3 if higher frequency photons be used, the photoelectric current will rise
4 When the energy of photons is $3.5 \mathrm{eV}$, the photoelectric current will be maximum